Pasted

var milliseconds = (DateTime.UtcNow - new DateTime (1970, 1, 1)).TotalMilliseconds;
 
// ActionScript 
(new Date()).time;
 
// C++
#include "time.h" time_t seconds; time(&seconds);
unsigned long long millis = (unsigned long long)seconds * 1000;
 
// Excel / Google Sheets*
=(NOW() - CELL_WITH_TIMEZONE_OFFSET_IN_HOURS/24 - DATE(1970,1,1)) * 86400000
 
// Go / Golang
time.Now().UnixNano() / 1000000
 
// Java
System.currentTimeMillis();
Javascript  new Date().getTime();